Effects of FDM 3D printing parameters on PLA biomaterial components dimensional accuracy and surface quality

Since precise manufacturing is very important in different industries, the produced part surface quality and dimensional accuracy have been brought to attention in recent years. In this regard, in Fused Deposition Modeling (FDM) as a prototyping method, controlling the process parameters in order to customize the produced part has been a value-added ability which should be considered. Optimizing the process parameters helps to enhance the mentioned products' properties. In this paper, influential process parameters, including print speed (PS), infill percentage (IP), and nozzle temperature (NT) were selected to examine. That was concluded NT increase from 195 degrees C to 240 degrees C, IP increase from 10% to 50% and PS decrease from 150 to 50 mm/min enhance dimensional accuracy including inner and outer ovality up to 30%, 53%, and 50%, respectively. PS is the most significant parameter on inner and outer ovality by 43.92% and 66.60% contribution, respectively. The density of the FDM part was affected mostly by the IP by 92.94% contribution which leads to the printed part density increment up to 13%. Other parameters have small effect on the density value. According to desirability method, that was resulted NT of 240 degrees C, IP of 50%, and PS of 54 mm/min are the optimum parameters. Besides, verification tests were carried out and a maximum error of 7.5% was reported, which shows optimization confidence. In the following, part geometry influence on the final part surface roughness and dimensional accuracy was examined. The experiments demonstrated that cube geometry has the least surface roughness of 20 mu m and dimensional error of 0.17 mm due to the independent motion of the axes. Also cone geometry has the highest dimensional error of 0.32 mm and surface roughness of 51 mu m which was due to simultaneous axes motion and lateral face lower than 90 degrees.